Does this mean that any English-speaker can, say, replace the Grail Psalms of the Liturgy of the Hours with the Revised Grail Psalms, and still pray in union with the Universal Church?

Yes, that's exactly what it means. Assuming you replace the old grail for the revised grail verse for verse, you are still praying licitly and liturgically, with the church.

Ben, dear friend...if this were accurate, wouldn't the Vatican have said in America, Canada, the UK, in Anarctica among any English-speaking scientists and so on?

It seems as if this would be problematical if a Canadian began praying in church with others but using...ah...BeniSoitLeSeigneur's fine posting just appeared and is well put.

Hi, BeniSoitLeSeigneur!

Scripture translations for liturgical use are determined by each conference of bishops, with the consent of the Holy See. I looked for information about whether the Revised Grail Psalms are approved for liturgical use in Canada, but found no indication of it. If you want, you can send an e-mail to the National Liturgy Office of the Canadian bishops conference, and let us know what information you receive.

From what I read on the net, the RGP has been approved everywhere else, and has appeared in print in Office books for Kenya and in a Lectionary for South Africa.

For public liturgy in English Canada, the liturgical books contain the only approved translations, psalms or anything else. The Catholic Book Of Worship III psalms (Grail (c) 1986) are also allowed, when sung from that book (which technically doesn't have all the recognition of a liturgical book). Anything else is illicit for public liturgy, although far from uncommon in practice.

Essentially the above was confirmed for me (by email) some years ago by a member of the Music Commission.

As far as praying the psalms privately, I must say the idea of "illicit prayer" sounds very odd to me. Remember the Pharisee and the publican! Unless you are bound to say the Office, as a cleric, then say it humbly with any psalm translation you like.

Thank you for the comments, everyone. Very helpful!

chonak, I also looked for this information in Canada and also found nothing. That's why I had recourse to this lovely forum. I will email the NLO and tell you which answer I receive.

Andrew Malton, this is a very clear answer, and I thank you. The fact that "illicit" texts are not-uncommonly used in public worship bothers me. I want to conform my prayer (and the prayer of all those praying with me) to that of the Universal Church, not to a private devotion. That is the only reason I desire to pray the "proper" translation of my national conference. I may have no Holy Orders or Vows, but praying the Hours "properly" is important to me regardless. This distinction between "conforming in public" and "doing what you like on your own" is very dissonant to me. Even the interior heart ought to pray with the Church, in my opinion.

bonniebede, the fact that shared arrangements exist between bishops' conferences is actually my primary cause for hope, in this case. As an example: the approved English Canadian Liturgy of the Hours translation is literally the same as the American Liturgy of the Hours in all aspects... at least, up until March 19, 2010, anyway! That is why I am fascinated to learn this answer.

francis, the editio typica of any liturgical celebration is always in Latin before it is in any other language. This means that it is always permissible to pray any celebration in Latin by anyone in the world.

I have another general question for everyone: since 2011/2012, has any word been given from the Vatican or Episcopal Conferences on whether it's licit to use the "new" translations of Collects from Mass to replace the "old" translations still in the LOTH?

The USCCB Committee on Divine Worship actually suggests using the revised collect translations in the Liturgy of the Hours. The trouble is that only some of the prayers from the Office match the Collect for the Mass of the same day in the original Latin. Weekdays in ordinary time tend to follow a different path, for example, using a set tied to the four week psalter. So if it is in fact the same prayer, I would use the newer translation, but it may well be a different prayer, in which case it would seem there is no choice but to use the one currently in the LotH, at least for public worship.

Where, please?

See here-- last bullet point under "Suggested Adaptations":

http://www.adoremus.org/0312Updates.html

sorry francis for the delay in replying, I've been away.
If you mean in Ireland, are we allowed do LOTH in Latin, then yes of course, it is the given language for every liturgical text everywhere in the Latin rite, and so always licit.
But maybe you meant something else?
We are starting an hour of Eucharistic adoration for the intention of the evangelisation of the parish, to include Vespers, hopefully sung, next Sunday. Hooray!
I'll be organising it, It will be in English, to simple psalm tones. so far we had one run through of this idea, me , and a 5 and 7 year old from our schola. They were enchanted by the idea of singing in church 'secretly' when no one else was there. As a test run, it really worked. the 7 year old has had a year in schola, though we don't do psalm tones there, she was singing psalms on her own competently straight away. the 5 year old, with no schola, took about two psalm verses to get into the flow, after that his only difficulty was occasional difficulties in reading.
If they can do it, anyone can.